1. Field of the Invention
This invention pertains to the preparation of rigid polyurethane foams containing alkylene oxide adducts of ethylenediamine.
2. Description of the Prior Art
U.S. Pat. No. 3,499,009 teaches the oxyalkylation of a polyamine by reacting first with 2 to 20 molar equivalents of ethylene oxide followed by 2 to 20 molar equivalents of a C.sub.3 -C.sub.5 vicinal alkylene oxide. These products are employed for the preparation of rigid polyurethane foams.
U.S. Pat. No. 4,209,609 teaches the oxyalkylation of toluenediamine with 3 to 5 moles of ethylene oxide and second with 1 to 5 moles of a C.sub.3 -C.sub.9 vicinal alkylene oxide. There is no teaching than an oxyalkylated ethylenediamine may be employed in the preparation of rigid polyurethane foams displaying good K-factor properties.